// Flex布局
@mixin flex($row: row, $align: center, $justify: center) {
  display: flex;
  flex-direction: $row;
  align-items: $align;
  justify-content: $justify;
}

/* arrow */
@mixin arrow($width: 32, $color: #333, $size: 3) {
  width: rem($width);
  height: rem($width);
  position: relative;
  &::after {
    content: '';
    width: 50%;
    height: 50%;
    box-sizing: border-box;
    border-top: #{$size}px solid $color;
    border-right: #{$size}px solid $color;
    position: absolute;
    top: 44%;
    left: 0;
    transform: rotate(45deg) translateY(-50%);
  }
}

/* rem计算 */
@function rem($px) {
  @return ($px / 100) + rem;
}